Electrically Conductive Hard Coatings for Aircraft and Missile Domes

Current IR systems are extremely susceptible to electromagnetic and radio frequency interference (EM/RFI) because they possess large apertures that present ideal front-door entry paths for EM radiation. Significant amounts of EM radiation (400 MHz - 18 GHz) can penetrate and couple to the IR sensor and supporting electronics, which leads to a substantial degradation in systems performance. EMI protection is critical to the survivability of the IR system and the system host (e.g., aircraft, satellite). Sienna Technologies, Inc., will investigate electrically conductive ceramics as erosion resistant EMI/RFI protective coatings for IR windows and radomes. We will deposit selected materials as continous film coatings by RF sputtering and study their shielding capability and IR optical transparency. Several compositions with different stoichiometries will be sputtered on window materials and heat treated. Resulting microstructures and sheet resistivities, optical transmission, and erosion resistance will be evaluated as a function of the composition and heat-treatment parameters. Deposition processes will be optimized to prepare test windows. Prepared windows will be tested for EM attenuation, IR transmission, and erosion resistance.